WALES' largest outbreak of cryptosporidium will be discussed "at the highest levels" in the UK.

The outbreak affected 231 people last year and was linked to the Llyn Cwellyn reservoir, which serves 70,000 people in North Gwynedd and South Anglesey. As a result of the outbreak, Dwr Cymru has installed a new ultra-violet light treatment to kill any residual cryptosporidium in the water.

The Chief Medical Officer for Wales, Dr Tony Jewell, will meet the chief inspector of drinking water in January to consider what lessons can be learned.